/- Copyright 2026 The Formal Conjectures Authors. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at https://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. -/ import FormalConjecturesUtil

Erdős Problem 1203

References:

open Filter Realopen scoped ArithmeticFunction.omega namespace Erdos1203

If $\omega(n)$ counts the number of distinct prime divisors of $n$ then let $F(n)=\max_k \omega(n+k)\frac{\log\log k}{\log k}.$

noncomputable def F (n : ) : := k : , (ω (n + k) : ) * (log (log (k : )) / log (k : ))

Prove that $F(n)\to \infty$ as $n\to \infty$.

@[category research open, AMS 11] theorem declaration uses 'sorry'erdos_1203 : answer(sorry) Tendsto F atTop atTop := True Tendsto F atTop atTop All goals completed! 🐙

It is easy to prove that $F(n)\geq 1-o(1)$.

@[category research solved, AMS 11] theorem declaration uses 'sorry'erdos_1203.variants.lower_bound : ε > 0, ∀ᶠ n in atTop, F n 1 - ε := ε > 0, ∀ᶠ (n : ) in atTop, F n 1 - ε All goals completed! 🐙 end Erdos1203